While human immunodeficiency virus (HIV) infection, which results in AIDS, is a relatively new infection in the human population, it has quickly risen to the foremost health problem in the world. HIV/AIDS is now the leading cause of death in sub-Saharan Africa, and is the fourth biggest killer worldwide. At the end of 2001, it was estimated that 40 million people were living with HIV infection world wide. The Centers for Disease Control (CDC) estimates that nearly 800,000 people are living with AIDS in the US, and 40,000 new cases diagnosed each year. While better treatment methods are now known to prolong the life of patients with HIV infection, there is still no cure.
Modern anti-HIV drugs target several different stages of the HIV life cycle, and several of the enzymes that HIV requires to replicate and survive. Some of the commonly used anti-HIV drugs include nucleoside reverse transcriptase inhibitors such as AZT, ddI, ddC, d4T, 3TC, and abacavir; nucleotide reverse transcriptase inhibitors such as tenofovir; non-nucleoside reverse transcriptase inhibitors such as nevirapine, efavirenz and delavirdine; protease inhibitors such as saquinavir, ritonavir, indinavir, nelfinavir, amprinavir, lopinavir and atazanavir; and fusion inhibitors such as enfuvirtide. However, in many HIV infected patients, none of these antiviral drugs, alone or in combination, is effective to prevent the progression of chronic infection or treat acute AIDS. The high mutation rate of the HIV virus and associated emergence of HIV strains resistant to drugs is one large factor that results in the inability to effectively treat HIV infection. New and better treatments are required for HIV infection.